The last spell of rain in Delhi was observed between November 25 and 27 and the pollution levels had also improved during this period. But thereafter, the pollution started to increase and is in poor to very poor category now. And in a few pockets, it is in a severe category. For the last week or so, winds are light during the daytime and calm during the night and early morning.
Moreover, the temperatures have also dropped leading to the formation of mist and shallow fog during the morning hours. Also, the pollutants, particularly dust particles, smoke particles mix with water vapour which lead to the formation of smog.
As winds are light in nature, they are unable to disperse the pollutants. If we talk weather-wise, then there are two factors which can decrease the pollution, either wind should be moderate to strong from a direction or there should be good rainfall activity which can help in washing away the pollutants.
Although we do not expect much increase in the wind speed, a fresh Western Disturbance over Jammu and Kashmir will induce a Cyclonic Circulation over the northern plains. Thus, it is likely that rains will commence in parts of Delhi and NCR by December 12. In fact, most parts of the plains including Punjab, Haryana, Rajasthan, and Uttar Pradesh will receive light to moderate rain and thundershower activities.
Hence, we can say there is a chance of pollution levels in Delhi improving and settling in the satisfactory to moderate category once again providing some relief.
The minimum temperature in Delhi is sliding day by day. For instance, the Safdarjung observatory today morning saw the minimum settle at 7.4 degrees Celsius which is the lowest of the season so far.
But now we expect the minimums to rise once again by two to three degrees in the next few days because of an approaching Western Disturbance and change in the wind direction.
Image Credits – The Indian Express
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